If they actually said "yeah, this car is turbocharged" and it's not, that is fraud.

If you saw the turbo "badge" or sticker or whatever and asked, and they said it was, or they wrote "TURBO" on the windshield and put it on the front of the lot that is fraud and you could contact an attorney. It would be best if you had an ad or some paperwork they wrote up stating turbocharged on it somewhere.

If you saw it and assumed, and it was never discussed during the sale I believe you are on your own.